Strategist: The Hero has great strategic skills. Before each battle a Hero with this skill may decide to develop plans that further the tactical ambitions of the warband. Choosing to have this model voluntarily miss the next battle due to the Hero's pondering means the warband gains +1 campaign point after the battle. The Hero does count for calculating warband rating as normal and determining the prices for selling wyrdstone/treasure. However, he does not count as part of the warband when taking Rout tests. Initial warband size is considered to be one model less during the battle. The Hero does not gain +1 Experience for surviving a battle since he did not take part in the fight

but then again some hired swords such as the Prospector have the Wyrdstone Hunter skill, which is another skill that mentions the user being a hero?Are Hired Swords treated as heroes for the purposes of skills?

Tricky. I would have said to allow it probably if it was almost any other skill. However, it would be broken to give this skill to a Hired Sword (especially a cheap HS) so I think it is best to treat it RAW and only allow it for the heroes in the warband.